Tech17 - Cost Based Optimizer - The Panel session

On Wednesday 5th December, I attended Tech 17. While it is a pain to organise getting there and back, I found in previous years that it was useful for me to go and find out what is happening in the industry. Cost Based Optimisation - The Panel Session Panelists: Jonathan Lewis Christian Antognini Richard Foote Nigel Bayliss Maria Colgan Slow Start This took questions from the internet and the audience, so it is a bit variable.

Broken PeopleTools Deployment Packages

The October Critical patch saw Oracle release Patch 26743107: PT 8.55.19 PRODUCT PATCH LINUX DPK. This is important to install because there was a serious security vulnerability in the performance monitor component which was easily exploitable over the network without authorisation. However, once the DPK was installed, looking at the Weblogic home, we can see that the October critical patch Patch 26519417: WLS PATCH SET UPDATE 12.1.3.0.171017

SessionHistory

Here is another note to myself about how to look at what sessions were doing over time. The situation was that we saw a lot of blocking sessions during a performance test. The developer wants information about the blocking sessions. To do this we want historical information from v$session, which helpfully tells us the blocking session, and also the SQL being run. This can be sampled every so often using a simple script, but Oracle have already thought about this and created v$active_session_history which you can use if you have licensed the Diagnostics pack.

PeoplesoftPerformance

PeopleSoft Performance Occasionally I have to diagnose a performance issue in PeopleSoft. This is a reminder to myself of the tools available and what I can check. PeopleSoft Ping This is a really useful tool because it gives real performance indications as to how the system as a whole is performing from the desktop to the database. The user can see the time taken at the browser, web server, application server and the database server for a simple query.

ApacheUcamWebauth

Installing Apache and Ucam Webauth on Centos/RHEL7 Apache is pretty easy: 1 yum install httpd Done. Ucam Webauth It is hosted on github, but won’t be much use to anyone who doesn’t have a need to authenticate users with the University of Cambridge’s single sign on which is called raven. I downloaded the SRPM from the raven page as suggested, and compiled it. The following packages are prerequisites.

DBLinks

Database Links Our PeopleSoft system suddenly started showing spikes in network usage. Users were complaining of slow performance. Enterprise manager shows big spikes in network waits. Strangely these don’t seem to be reflected in the SQL. The table on the left doesn’t have as much beige/grey as the one on the right. Lets click on network and see what the waits really are. SQL*Net message from dblink. Ok brilliant. It is confusing why we don’t see it reflected in the SQL, but we know it is a dblink that is slowing things down.

Criticalpatch

Oracle Critical Patches It was critical patch Tuesday this week. Because of the time differences between here and the USA we actually only get to find out about the critical patches on Wednesday, though there is a pre release announcement. With software as complex as Oracles you can pretty much guarantee that there will be serious bugs somewhere in there which need patching every quarter. Considering the types of organisations that run Oracle - the ones who can afford to pay the license fees, i.

Jenkins On Centos

Install Jenkins. Automatically? The documentation for Jenkins is pretty sparse, but fortunately a colleague had set up Jenkins already, and was able to give me some pointers. The idea is to use the Apache web server as a reverse proxy to access Jenkins. This can also take care of user authentication. Prerequisites So first of all download Java from Oracle. I download it manually and keep it in case the link changes.